Research on water inrush mechanism of fault coupling bed separation with fully-mechanized sublevel caving of ultra-thick coal seam
MA Lianjing1,2 ,ZHAO Baofeng3 ,XU Huijun4 ,CAO Haidong3
长安大学 环境科学与工程学院长安大学 旱区地下水文与生态效应教育部重点实验室中煤科工集团西安研究院有限公司国家能源投资集团有限责任公司
为了研究在复杂条件下断层-离层耦合溃水的机理及制定相应的防治水措施,在分析了老虎台井田地质、水文地质和开采条件的基础上,结合水害事故,采用数值模拟和相似材料模拟两种方法,对特厚煤层分层综放开采工作面“两带”发育高度、断层和离层空间形成特征进行了定量化研究,工作面回采后的冒采比和裂采比分别为4.98~5.42和7.10~7.30;断层空间形态和大小主要受到断层落差和与工作面距离影响;离层空间主要形成于不同岩性接触面附近。基于工作面顶板断层和离层空间形成、充水和溃水过程分析,揭示了断层-离层耦合溃水机理:上分层工作面回采导致覆岩中产生断层和离层空间,在接受含水层的持续补给后形成断层和离层水体,下分层工作面回采产生的垮落带波及至水体后发生溃水事故,与以往断层水害和离层水害相比,具有以下特点:断层和离层同时作为水害事故的充水水源和导水通道;垮落带是导致水害发生的主要因素;水害的孕育和发生分别在不同的工作面。针对水害特点提出了相应的防治水方案,首先对研究区进行水害威胁程度分区,受水害威胁轻及较轻区域的煤炭资源可以正常回采,受水害威胁较重及重区域的煤炭资源必须采取以下措施方可回采:注浆充填已形成的断层和离层空间,疏放已形成的断层和离层水体,减少工作面回采对覆岩中断层和离层水体的扰动。根据典型工作面的安全回采,初步验证了溃水机理的正确性和防治水方案的可靠性,下一步将根据井上、下工程验证,补充和完善防治水措施。
In order to research the water inrush mechanism of fault coupling bed separation under the complex condi- tion and formulate corresponding water disaster control measures. Based on the analysis of geological,hydrogeological and mining condition in Laohutai coal mine,combined with water inrush accident,numerical simulation and similar material simulation were used to research “two zones” development rule of working face,the space formation charac- teristics of fault and bed separation with fully-mechanized sublevel caving of ultra-thick coal seam. The caving to min- ing ratio and fracturing to mining ratio are 4. 98-5. 42 and 7. 10-7. 30. The spatial form and size of faults are mainly affected by the fault throw and the distance from the working face. The bed separation space is mainly formed near the contact surface of different stratum. Based on the analysis of formation,water filling and water inrush process of fault and bed separation on the roof of working face,water inrush mechanism of fault coupling bed separation were find out: the mining of upper layer working face led to fault and bed separation space,then the space were filled with water from aquifer continuous replenishment,the water inrush was happened when the caving zone connected water body after lower working face mined. Compared with the previous water disaster caused by fault and bed separation,the water in- rush of fault coupling bed separation has the following characteristics:the fault and bed separation are water filling source and channel of water disaster at the same time;The caving zone is the main cause of water disaster;The gesta- tion and occurrence of water disaster are in different working face. For water damage characteristics,the corresponding project of water control was put forward. First of all,the research area is partition according to water disaster threat de- gree. Then,the coal resources not threatened by water disaster can be mining. The coal resources threatened by water disaster can be mining after the following measures:grouting and filling the space of fault and bed separation,drainage the water of fault and bed separation and reducing the disturbance from working face mining to the water of fault and bed separation. According to the safety mining of typical working face,the correctness of water inrush mechanism and the reliability of water disaster control scheme are preliminarily verified. In the next step,the water disaster control measures will be supplemented and improved according to the engineering verification on the ground and underground.
ultra-thick coal seam;fully-mechanized sublevel caving;numerical simulation;similar material sim-ula- tion;water inrush mechanism
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会